PRESIDENT ACTS QUICKLY AFTER REPORT

WASHINGTON -- President Reagan moved dramatically Friday to revive his troubled presidency by replacing Donald T. Regan with former Sen. Howard H. Baker Jr. as the White House chief of staff.

Reagan made the announcement of the major staff change a day after a special presidential review commission harshly criticized his detached style of management and blamed Regan for "chaos" in the White House after disclosures of the secret Iran policy.

Reagan included a pointed statement in the announcement in which he vowed to reorganize the White House staff so it could move aggressively during the remainder of his presidency.

The appointment of Baker, a former Senate majority leader, drew a quick and bipartisan favorable response from Congress, where legislators saw it as an indication that the president would take the necessary action to address the panel's criticism.

Regan, a blunt former Wall Street executive who had been the center of persistent attacks through his White House tenure, had hoped to wait until Monday before resigning. But at the president's insistence, he offered his resignation in a brief statement that apparently reflected irritation with the decision to announce the move Friday.

The statement, issued late Friday by the White House, said:

"Dear Mr. President:

"I hereby resign as chief of staff to the president of the United States.

"Respectfully yours, Donald R. Regan."

The president said that he had accepted the resignation with "regret" and that Baker was a man of "unquestioned integrity and ability."

"I am enormously pleased that he is willing to take on this responsibility and to help me organize the White House staff for an aggressive two years of work," the president said.

Regan, leaving the White House Friday afternoon before the announcement was made, looked somber. A senior White House official said he was disillusioned and saddened by the actions of "some people" inside and outside the White House who had conducted concerted campaigns to oust him.

The official said Regan could not understand why so many people thought the "quick fix" to the White House problems was to have him resign immediately. He was also saddened by criticism that he had sought to hold on to the position even though his staying hurt the president.

But Nancy Reagan, who had led a three-month private effort to oust Regan that had become increasingly acrimonous, said she was pleased about the replacement.

"I am delighted he will be with us," she said of Baker.

The president had sounded out at least two other candidates before selecting Baker. The two, Paul Laxalt, a former Republican senator from Nevada, and Drew Lewis, the chief operating officer of Union Pacific Co., had both expressed reluctance.

The choice of Baker was regarded by White House aides as an attempt by the president to appoint a longtime Washington hand who is widely respected in Congress and regarded as having keen political instincts.

The staff moves came as Reagan began a series of meetings, to stretch into the weekend, on how to combat the most serious crisis of his presidency. In a highly detailed report issued Thursday by a special review board examining the Iran-Contra affair, the president was portrayed as confused and his style of detached management came under criticism.

One of Baker's first tasks will be to shepherd Reagan through a nationally broadcast speech next week, in which the president is expected to offer his response to the report.

White House officials and others close to the president said Baker's selection had come after Reagan met Thursday with Laxalt in the living quarters of the White House. Laxalt said he had told the president that he could not accept the position because he was considering seeking the Republican presidential nomination in 1988.

"I told him it would create a credibility problem," Laxalt said, adding that Reagan did not make a formal offer.

Reagan had also discussed the possibility of Lewis's becoming chief of staff in a telephone interview, but Lewis told him that he could do so only on a temporary basis, a source said.

"He's not in a position to come on board," the source said.

The source said it was Laxalt who first mentioned Baker to the president as a possible choice. But Laxalt said the former senator would accept the position only if asked directly by the president, and not by Regan.

Some aides to Baker have said Regan misrepresented his position to the president on whether he was willing to accept an appointment as director of central intelligence before Reagan chose Gates earlier this month.

According to a source, Reagan reached Baker Thursday at a zoo in Florida where he had taken a grandchild. Returning to Washington Friday, he met with the president and accepted the position.

Baker, viewed as a Republican moderate, had challenged the president in the 1980 Republican primary, but they developed a close working relationship once Reagan was elected. Baker was Senate majority leader from 1980 to 1984.

The appointment, which is expected to move Baker out of contention for the 1988 presidential race, gives Reagan his third chief of staff since his first election in 1980. Coming at a time in which a new national security adviser, his fifth, is also in place, it is expected to alter the Reagan White House dramatically in its last two years.

White House officials said that they expected Baker to make several important staff changes and that some of the remaining senior aides loyal to Regan would leave. They are expected to include W. Dennis Thomas, a presidential assistant; Peter J. Wallison, the White House counselor, and possibly William Ball, the chief legislative strategist.

HIGHLIGHTS

-- President Reagan replaced Donald Regan with former Senate Majority Leader Howard Baker as the White House chief of staff.

-- Reagan vowed to reorganize the White House staff so it can move aggressively until the end of his term in 1989.

-- In Congress, Republicans and Democrats alike praised Reagan's selection of Baker for the White House job.

-- Regan, who had hoped to delay his departure until Monday, resigned Friday at the president's insistence. Apparently irritated by Reagan's decision to make the announcement immediately, Regan kept his resignation letter brief and to the point:

Dear Mr. President:

I hereby resign as Chief of Staff to the President of the United States.